Process for decolorizing and stabilizing oils



July 28, 1925 1,547,682

P. W. PRUTZMAN PROCESS FOR DEcoLoR'i'ziNG AND STABILIZING OILS Filed Apfil 19, 1921 CONTH/NER A TT ORNE Y.

. atcnted July 28, 1925,

UNI E ATES PATENT oFFicE,

PAUL w. rnu'rzmam or LOS ANGELES, cnuronma, nssrono'n To GENERAL PETROLEUM oonroimrron, A conrona'rron or c'nuromrmv Y IPROCESS DECOLORIZING AND STABILIZING OILS.

. -A pp1i'cati0n filed April 19, 1921'. Serial uu ieas'zo.

To all whom it may aoncermr v Be it known that I, PAUL W, PRU'rz-MAN, a citizen of the United States, residing at Los Ange-les, in the county of Los Angeles I 'therewith of a decolorant material which ab- Y heretofore mixed with the mixture is thoroughly agitated to allow sorbs certain constituents of such oils and the decolorant material being afterward separated from the base o-il.- The resulting product is an 011 of much lighter color than the untreated oil and therefore-of, more com-' mercial value.

My invention' has for its object the provision of a process whereby. such operations may be performed with greater facility than possible and with a material're' duction in the amount of materials required to produce the desired change in color.

In the present state of the art of decolorizing oils the decolorant materials are he 011 in an agitator wherein the decolorant to act upon the body of oil.

I plied are heated to a Heretofore it has been considered necessary to perform such operations at temperatures below 250 F. as oxygen from the air combines with the oil if present when the oil is more highly heated and causes a darkening of the product which partially offsets the work performed by the decolorant.

The objects of my invention are attained by subjecting the 'oils to decolorizing proc-.

esses under temperatures up to 800 F; which is made possible, as hereinafter set forth, by excluding air from. contact with the oil while the oil being decolorized is in.

this highly heated condition, the means for excluding air being the passage of an oxygen free gas, or vapor over the surface of the heated oil during the operation."

a If the oils to which my invention is-apmoderately elevated temperature, say 250 F. in contact with an adsorbent decolorizing agent, a certain de- -ree of decolorization or reduction in color I p foiljand in the'manner as hereinafter set is obtained. I have discovered that at progressively higher temperatures the color is progressively further reduced, (by the use air and gases ing up to my invention andis very important, the value of certain decolorants at moderately high temperatures,say 250 F. being multiplied from 3 to 5 times when the oil with the deco-lorant present therein, is heated to a temperature. of say 600 F., thus correspondingly reducing the amount and cost of the decolorant consumed and to be handled and of oil loss by entrainment 'in the spent decolorant. f v

The reason for this increase 'in decolorizing'value of the adsorbent at high temperatures seemingly resides in the increased molecular activity of the oil at incr temperatures in deeper enetration of oil into the grains of the ecolorant, in the more complete disengagement of adsorbed from the decolorant, and in certain condensations of the colored bodies in the oil by which they are rendered more amenable to adsorption by the decolorant.

vention have the temperature thereof raised much in excess of 250 F., while exposed to This increased When the oils to be treated under my in- I Russuw we to. a certain point which varies with different contact with the air, they enter into combination with the oxygenthereof, with theformation of dark-colored and od-orous bodies, by which the bleaching action of the decolorant is in part offset and nullified.

-At still higher temperatures this oxidizing reaction. becomes more rapid and complete, and at the temperatures (mainly above 3 50 F.,) at which I prefer to work, this oxidation' will entirely nullify the-action of the 'decolorant and destroy of the oil product, if air is allowed access the commercial value to the oil while so highly heated. These objectionable features are all eliminated when working under my invention with oils, L

the temperatures of which are raised much in excess of 250 FT, due to the fact that I prevent the access of 'air to the oil by means of,, or through the medium of, a stream of flow current of a gas or vapor passed over the surface of the forth. t

*Whn oils with an adsorbent intermixed therewith are treated under temperatures non-oxidizing much in excess of 250 they crack or in other words, suffer a heat decomposition,

by which decomposition products of a vol'atile nature, of an ofiensive odor and sub ect to oxidation and darkening on exposure to air at ordinary temperatures, are formed. These products, if allowed to remain in the oil, will render it valueless by reason of their odor, and thus the color of the oil will be unstable. Under my method invention for the treatment of oils in the presence of an adsorbent material, these products are volatilized and thrown out of the oil by the high temperatures used, most readily at a temperature of above 350 heat, and are then\ swept off and carried away by the stream of gas passing over the surface of the heatedoil, the oil being maintained excluded from contact with the atmosphere during the period of treatment. By this means the color of the oil is stabilized, and any objectionable odor due to a cracking of the oil, is removed, and as air is likewise excluded or maintained out of contact with the oil, the full increase in value of the decolorant at elevated temperatures is realized, and the desired economy of material attained, thereby permitting a given quantity of oil to be treated with a less or smaller quantity of adsorbent than heretofore, and the production of an oil of a better color and permanency than. otherwise would take place or result.

Any suitable form of an apparatus may be employed for the carrying out of the method invention. I have illustrated in the accompanying drawings a simple, efficient and practical apparatus for the carrying out of the invention, wherein the said apparatus is disclosed diagrammatically, portions of certain parts thereof being broken away.

The apparatus used comprises a deco-lorant mixing vat 1 which is supplied with decolorant from a hopper 2, a retort 3 in which the oil and decolorant may be raised to the desired temperature, a receiver 4 .in which the decoloirant may fully function and the mixture may be-ttllowed to cool sufficiently to permit its being transferred to the final process of separation, a gas tank 5 from which a non-oxidizing gas is supplied to the various pieces of apparatus to displace the aif which would otherwise react with the o1 .As oil atcomparatively low temperatuFes does not readily enter into reaction with oxygen, it is unnecessary to exclude air from the mixing vat 1. The oil to be decolorized is supplied to the mixing vat 1 from any exterior source not shown through an 'inlet pipe and a valve 12 and is thoroughly mixed with deoolorant supplied from the hopper 2 having a control gate 15 which discharges into thevfeed spout 16. Theagitation is accomplished by blades mountaeaaeea ed upon a shaft 21 and revolved by any suitable gearing arrangement 22.

From the mixing vat 1 the oil and decolorant mixture is transferred to the retort 3 through the valve 25 and the piping 26. In the retort 3 the mixture is raised to the desired temperature by heat supplied by any suitable means such as a burner 31, and throughout the heat application the remaining space 32 within the retort is maintained As it is desirable to introduce the mixture from the agitation process in mixing vat 1 into the retort 3 and the receiver 4 under conditions that will not cause the oxidation of same, valves and 46 in gas supply lines 50 and 51 are opened to allow free passage of non-oxidizing gas from the container 5 into these chambers to effect the the removal of the air therein contained. A continuous circulation of the gas is provided for by the return lines and 61 which meet at a T 63 and are connected .to a pipe 64 lea-ding to a centrifugal blower 65 having connection with the container 5 through piping 66. In starting the apparatus, the blower 65 exhausts the air content of the retort 3 and the receiver 4 through the return piping 60 and 61 and discharges same through the outlet port 70 of a threeway valve 71 in the line 66, and the gas entering the're'tort and the receiver through the valves 45 and 46 displaces the air as it is exhausted by the blower and follows said air up through the return pipes 60 and 61. When gas begins to flow through the port 70 of the valve 71, the operating lever 72 is actuated and the flow of gas is directed through the piping 66 into the container 5.

The mixtures entering the retort 3 and the,

i ant, thereby decreasing the amount required to accomplish the desired results as well as greatly reducing the time required for performance. J

v The above process is applicable to the decolorizing of oils by clay, kaolin, fullers earth, filtering clay, bone or other animal or vegetable char, or any other equivalent deer, colorizing agent.

While I have described the preferred means of maintaining the oil during treatment out of contact with the atmosphere, and the preferred means for removing such gaseous vapors as may be thrown ofi from the oil While treated in the presence of adsorbent material at higher temperatures than are referred to, and the minimum temperature of which is approximately 350 F., I do not wish to be understood as restricting or limiting my method of invention to such particular means, inasmuch as my invention resides in, and that which I wish to be understood as claiming as broadly as the state of the art will permit, the method of treating a body of oil in the presence of an adsorbent material and while maintained out of contactwith the atmosphere and main taining a body of air during the heat temperatures of the oil utilizing means for removing or carrying away any gaseous vapors which may be thrown ofl from the oil during its treatment.

I claim as my invention:

'1. The method of purifying and partly decolorizing hydrocarbon oils which consists in intermixing with'the oil to be treated. a powdered solid adsorbent, heating the mix ture in a substantially closed vessel to a temperature at whichthe oil decomposes appreciably, to permit the adsorbent to withdraw the maximum quantity of coloring matter from the oil, steaming the hot mixture to carry off the decomposition products evolved, and finally separating the spent adsorbent and its contained coloring matters from the decolorized oil remaining in the vessel by mechanical means.

2. ,The method of purifying and partly docolorizing hydrocarbon oils which consists in intermixing with the oil to be treated apowdered solid adsorbent, heating the mixture in a substantially closed vessel to a temperature above 350 F. to permit the ad SOl'bBht to withdraw themaximum quantity of coloring matter from the oil, steaming the hot mixture to carry ofl rthe decomposition products evolved, and finally separating the spent adsorbent and its contained coloring matters from the decolorized'oil remaining in the vessel bv mechanical means.

In testimony whereof, I have hereunto set my hand atLos Angeles, California, this 13th day of April, 1921.

PAUL W. PRUTZMAN. 

